These are the Mobiles App store listings we submit too and the image sizes we develop are all inclusive.
If you want to create your own branded images, these are the size requirements:
GOOGLE PLAY STORE
Graphic Assets
Phone and 10-inch tablet
5 images – 512px width x 512px height including a your logo
1 High-res icon Default – English 512 x 512 32-bit PNG (with alpha)
1 Feature Graphic Default – English 1024 w x 500 h JPG or 24-bit PNG (no alpha)
1 Promo Graphic Default – English 180 w x 120 h JPG or 24-bit PNG (no alpha)
APPLE iPHONE STORE
Find us on – Google Play Store Android | Apple | Amazon